Microlipoinjection is a process in which fat is taken by a cannula from one spot in the body and reinjected in another place in the body. Microlipoinjection has also been known as liposuction with fat transfer or fat transplantation. In general, microlipoinjection is performed to treat divots and scar indentations from trauma to the face or body, such as may occur as a secondary effect of domestic trauma, surgery or infection. Microlipoinjection can also be used to treat the effects of the loss of the subcutaneous layer of fat due to the normal aging process, either alone or in combination with facelift and fat grafting techniques. Microlipoinjection can also be used for providing filler to reapproximate weakened vocal chords, fill sinuses, or partially close incompetent valves.
Up to about 1990, there were few artificial filler substances available to surgeons. Accordingly, surgeons used human bone, collagen and fat as fillers. However, the use of fat was not very successful, because the instruments and techniques were not sufficiently refined. For example, 50% of the fat may not have lived through the transplantation process. As a result, surgeons would need to implant more fat than would be required if all of the fat survived the process, or the transplantation process would have to be repeated multiple times.
More recently, a number of filler substances, such as Restylane Hyaluronic Acid, Collagen, Fibril, ePTFE (Teflon®), Hylan B Gel, Artecol, BioBlastique and have been used. These substances have proved effective at filling small areas, but the cost for larger areas has become prohibitive. For this reason, as well as interest in the “natural substance” concept, surgeons and their patients have again looked at using fat as a filler.
With the renewed interest in using fat as a filler, techniques have been refined to provide a better fat graft “take” with revascularization. However, the instruments and devices conventionally available to perform the procedure remain clumsy and ill-suited for the procedure. As a result, the procedure has remained difficult to perform, cumbersome, time consuming, expensive and relatively unsuccessful. For example, the conventional process employed in connection with microlipoinjection comprises about 10 steps, some of which can cause damage to a significant percentage of the fat cells. In addition, it is necessary to maintain strict sterility throughout all of the steps. However, sterility is difficult to maintain in connection with centrifuging, which is performed separately from the sterile operating field, and involves ancillary personnel. The basic steps of the conventional microlipoinjection process can be summarized as follows:
Step 1—Liposuction of fat from the donor area, the fat going into a large syringe. The suction aspirate contains the wanted fat, plus the unwanted blood, serum, anesthetic agent, etc. These later substances must be removed for the best lipocyte survival rates.
Step 2—Fat is transferred into several smaller syringes that will fit into a centrifuge. Every time the fat is transferred to another syringe, there is more destruction of fat cells secondary to pressure of the plunger forcing the fat through the narrow outlet of the syringe into the input luer of the next syringe. Caps are placed on the end of the syringe to prevent loss during centrifuging.
Step 3—Centrifuge for several minutes or until the contents are in three layers: the top layer is triglyceride oils, the middle layer is fat, and the lower layer is the remaining blood cell debris.
Step 4—Decant off the top liquid oil and serum from the centrifuge specimen.
Step 5—Place the plunger in the syringe, tip syringe upward and squirt out the red cells and debris, leaving the residual fat in the syringe. Sometimes this has to be repeated, including repeat centrifuging, a number of times for proper separation.
Step 6—Treat contents with irrigation solutions, platelet rich plasma (PRP), albumin, growth hormone, or other substances, by aspirating this substance into the syringe. These substances are considered helpful in ensuring the viability of the lipocyte (fat cell). Some of these substances aid in angiogenesis (establishment of blood vessels) or treat in a manner that encourages lipocyte survival.
Step 7—Gently mix by circular motion.
Step 8—Centrifuge again.
Step 9—Decant off liquid additive.
Step 10—Put the plunger back into the syringe, place an injection needle on the tip and inject the fat into the divot or wrinkle. This injection is conventionally done manually with a control syringe or special manual mechanical gun.
The washing and/or treatment of tissue, for example to remove broken fat cell walls and contents, to remove chemicals introduced during the tissue removal process, and to treat the removed tissue, is often desirable. However, the washing and/or treatment of tissue comprising fat using irrigation solutions is particularly problematic, because conventional techniques for treating or washing the tissue often result in traumatic events for the tissue cells and increase the chance of microbe contamination. In particular, conventional washing techniques have been time-consuming and expose the tissue to the hands of the surgical staff, exposes the tissue to the ambient air, and passes the tissue through different devices. This is because of the techniques involved: first removing the tissue from the body; placing the removed tissue into a wash container; manually mixing sterile solution with the tissue; stirring the mixture; filtering it; centrifuging it; and then transferring it to the appropriate syringe for reinjection. Accordingly, it would be desirable to reduce the time required to rid the specimen of unwanted, broken fat cell walls, broken fat cell contents, as well as chemicals that have been introduced for anesthesia and vasoconstriction and/or to otherwise treat the removed tissue. In addition, it would be desirable to reduce the trauma to cells of removed tissue, and to reduce the chance of contamination of such tissue.